To try this demo out:

1. Build and run the app:

   $ ./demo.sh 
   Requirement already satisfied: pip in ./pex.venv/lib/python3.7/site-packages (20.3.3)
   Requirement already satisfied: pex==2.1.24 in ./pex.venv/lib/python3.7/site-packages (2.1.24)
   Sending build context to Docker daemon  35.59MB
   Step 1/4 : FROM docker.io/nginx/unit:1.21.0-python3.7
    ---> 0c9cddb57740
   Step 2/4 : RUN apt update && apt install -y python3 python3-distutils
    ---> Using cache
    ---> 8da196b090b3
   Step 3/4 : COPY apigateway.pex /app.pex
    ---> Using cache
    ---> 51a89695cd78
   Step 4/4 : RUN PEX_TOOLS=1 ./app.pex venv /app
    ---> Using cache
    ---> 39cfb7e1c0b0
   Successfully built 39cfb7e1c0b0
   Successfully tagged pex-issues-1181:latest
   /usr/local/bin/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, launching Unit daemon to perform initial configuration...
   2021/01/20 18:19:01 [info] 11#11 unit started
   2021/01/20 18:19:01 [info] 13#13 discovery started
   2021/01/20 18:19:01 [notice] 13#13 module: python 3.7.3 "/usr/lib/unit/modules/python3.7.unit.so"
   2021/01/20 18:19:01 [info] 12#12 controller started
   2021/01/20 18:19:01 [notice] 12#12 process 13 exited with code 0
   2021/01/20 18:19:01 [info] 16#16 router started
   2021/01/20 18:19:01 [info] 16#16 OpenSSL 1.1.1d  10 Sep 2019, 1010104f
   {
     "certificates": {},
     "config": {
       "listeners": {},
       "applications": {}
     }
   }
   /usr/local/bin/docker-entrypoint.sh: Looking for certificate bundles in /docker-entrypoint.d/...
   /usr/local/bin/docker-entrypoint.sh: Looking for configuration snippets in /docker-entrypoint.d/...
   /usr/local/bin/docker-entrypoint.sh: Applying configuration /docker-entrypoint.d/config.json
   /usr/local/bin/docker-entrypoint.sh: OK: HTTP response status code is '200'
   {
     "success": "Reconfiguration done."
   }
   
   /usr/local/bin/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/...
   /usr/local/bin/docker-entrypoint.sh: Stopping Unit daemon after initial configuration...
   /usr/local/bin/docker-entrypoint.sh: Waiting for control socket to be removed...
   2021/01/20 18:19:01 [notice] 12#12 process 15 exited with code 0
   2021/01/20 18:19:01 [notice] 12#12 process 16 exited with code 0
   
   /usr/local/bin/docker-entrypoint.sh: Unit initial configuration complete; ready for start up...
   
   2021/01/20 18:19:01 [info] 1#1 unit started
   2021/01/20 18:19:01 [info] 35#35 discovery started
   2021/01/20 18:19:01 [notice] 35#35 module: python 3.7.3 "/usr/lib/unit/modules/python3.7.unit.so"
   2021/01/20 18:19:01 [info] 1#1 controller started
   2021/01/20 18:19:01 [notice] 1#1 process 35 exited with code 0
   2021/01/20 18:19:01 [info] 37#37 router started
   2021/01/20 18:19:01 [info] 37#37 OpenSSL 1.1.1d  10 Sep 2019, 1010104f
   

2. Test the app:

   $ curl -s localhost:8000 | jq .
   {
     "Hello": "World"
   }
   $ curl -s localhost:8000/items/42?q=Slartibartfast | jq .
   {
     "item_id": 42,
     "q": "Slartibartfast"
   }